Adam LaRoche could leave via free agency, creating a hole at first base.

As we transition into offseason mode, we'll start by breaking down the Nationals' roster by position (infield, outfield, catcher, rotation and bullpen) this week and examine where things stand at season's end and where things might stand moving forward. Today's position: Infield…

1B ADAM LaROCHEStats: 154 G, 647 PA, 33 HR, 100 RBI, .271 AVG, .343 OBP, .510 SLG7 E, 6.1 UZR, 3.8 WAR2012 salary: $9 millionContract status: $10 million mutual option in 2013, if declined becomes free agentWhere he fits in: Perhaps the Nationals' team MVP, LaRoche's contributions this season were immeasurable. He was the club's most consistent offensive player, setting a career-high in homers and matching his career-high in RBI. He played Gold Glove-caliber defense at first base, saving his teammates from being charged with countless errors. And he was a calming and popular presence in the clubhouse. For all of those reasons, the Nationals want to bring LaRoche back for 2013. The problem? He's likely to decline the one-year, mutual option, wanting a longer-term deal. The Nationals are open to that, and the two sides have begun preliminary talks. They'd ideally like to get something done before LaRoche is allowed to become a free agent (five days after conclusion of the World Series) so these next couple of weeks could be significant.